Military operations increasingly rely upon electronic warfare. Electronic warfare may include the use of electromagnetic signals for communication, surveillance and position information. For example, aircraft and ground vehicles may include receivers for receiving radio navigation signals from a satellite navigational system to determine a current location. Precision guided munitions (PGM) may also include satellite navigation receivers to determine a current position and to effectively navigate a path toward a desired target. Precision guided munitions may include a receiver for receiving radio navigational signals whereby the radio navigational signals may be processed to determine a position of the PGM.
In order to thwart an enemy's electronic warfare capability, a second party may engage in an electronic attack to disrupt the navigational capability of an enemy. A navigational receiver may rely upon the receipt of multiple signals from a plurality of navigational satellites to determine its current position. An electronic attack may include one or more emulator spoofers, which refer to devices which generate emulator spoofer signals of the navigation signals which may be advanced or delayed in time. An emulator spoofer may have multiple effects on a navigation receiver. An emulator spoofer signal may deceive a receiver whereby the receiver generates undetected and erroneous navigation information. Emulator spoofers may create signal modulations containing subtle deviations from specification that lead to navigation errors. Emulator spoofer signals may resemble an authentic signal in many signal properties; consequently, navigation receivers may process a spoofed signal rather than an authentic signal. If a radio navigation receiver receives and processes a spoofed signal instead of the authentic signal, the receiver may make an incorrect computation of the transmission time, which will lead to a navigation error in a time-of-arrival based navigation system. Also, an emulator spoofer may generate a plethora of emulator spoofer signals whereby a navigation receiver is not capable of generating navigation information.
Conventional solutions to the transmission of emulated signals have employed signal encryption. However, encryption keys used to generate and acquire the encrypted signals may be compromised. Consequently, a method and system to mitigate emulator spoofer signals is necessary to thwart counter-attacks on navigational capability.